To elaborate on the wrong way round built aluminium yacht. Now if you weld and tack trough the honeycomb‘s squares’ (320 mm frame pitch by 160 mm stringer pitch) from the outside a light gauge aluminium innerskin than you have a near impenetrable hull. Note: the designer was NOT involved in the ‘Titanic’ but cautiously used the word ‘near’ while the word ‘absolute’ may have bordered nearer to the truth. By water tightening the inside, the inescapable warping of the welded innerskin does not need ‘straightening’ out because wood paneling/cladding will cover it. Welding an outer-skin however requires considerable grinding and filling to ensure an unhindered water flow, so essential for fast sailing. Established aluminium boat builders may ridicule the method for fear of losing a nice fat expensive job because anyone with some MIG experience can do it. Being a cold-moulded ply ‘expert’ for some 50 years now and lately concentrating on GRP composite we are elated by the wake-up call from MR.Julz for opening new avenues for us and realizing that our workshop and equipment, can handle it. Thanks Mr. Julz for indirectly teaching me (and the world) how to make the most cost-effective strongest durable fastest etc yacht. One is never too old to learn (I am 74 now). I bumped into
http://Yoavraz.googlepages.com/saili...edvs.windspeed. an article, which ascertains that the performance of the 30 footer was NOT exaggerated. From a dissertation of Prof Ir J.Gerritsma (University of Delft) (report Nr 600 A) comes a proof that our tapered mast (however not existing at the time) indeed improves sailing in a seaway by reducing the Longitudinal Moment of Inertia ( Radius of Gyration) of the whole yacht. In addition, Prof Marchay proves thus a more effective airflow around the mast (so did the old IOR rating rules who deducted about 20% from the mainsail area due to the mast’s frontal area. We substantiate our moderate claim of 6% increase in speed on numerous factors. Again, a tapered aluminium mast is more cost effective and durable than a carbon fiber one and carries no rating penalties. Prospective buyers should judge a design on the hull lines because they are the ones, which ‘predict’ the yachts performance but a nice side view, interior layout or hollow rhetoric don not. Unless other designers show their lines, beware: you may be buying a cat in a bag, and buying a ‘name’ more than a yacht!